Fuse-plug.



J. A. DUGAN.

'FUSE PLUG. APPLICATION FILED 0011,1917.

Patented June 11, 1918.

INVENTOR WITNESSES ATTORNEY in the circuit after ondary wire Parana orrron.

"UNITED srArns JOSEPH A. DUGAN, or nous'roiv', TEXAS,

ASSIGNOR 03E" ONE-HALF TO WILLIAM A.

VINSON AND JOE CATHRINER, BOTH 0F I-IOUSTQN, TEXAS.-

FUSE-PLUG.

. To all whom it may concern:

*ful Improvements in Fuse-Plugs, of which the following is a specification.

This invention is a fuse plug and has torits principal object the production of a safety structure which is suitable of prolonged usage.

Another object of this invention is the production of a fuse plug wherein a plurality of fusible wires are employed, there by permitting'a new wire to be substituted the original wire has melted, thus prolonging the life and usage of the/fuse plug.

A still further objectof this invention is the production of a fuse plug wherein one fusible wire is in the original circuit in which the fuse plug is used, although after this Wire has melted due to an over voltage or charge, a new wire may be brought into the circui Another object of this invention is the production of a fuse plug, wherein the secis ordinarily not in use, although the ends thereof are connected thereby allowing a trigger to be swung into engagement with one of the ends and into engagement with the contact plate, thereby bringing the auxiliaryor secondary fusible wire into use.

With these and other objects in view, this invention relates to certain novel combina tions, constructions, and arrangements of parts, as will be hereinafter fully described. and claimed.

In the accompanying drawing I have dis- I closed oneform of my invention, in which,

.Figure 1 is a central vertical section through the fuse plug, and

Fig. 2 is a bottom plan view of the fuse plug.

. {Referring more specifically to the accom-- bynumerals it will be, the fuse anyin drawin eenullt 1 indi atesthe shell of plug. This shell 1 is preferably of an elongated cylindrical construction as is the ordinary form of fuse plug now in use. This shell 1 has a conical portion 2 adjacent its lower end and this conical portion 2 is provided with a central opening 3, formed thcrcth rough as shown clearly, in Fig. 1.

Patented June 11, 1918. Serial No. 194,252.

grounded upon a supporting structure by the sleeve 6.

The contact plate 7 is positioned upon the lower or inner end of the conical portion 2, so as to normally close the concentric opening 3 formed in this conical portion as shown. in Fig. 1. The contact plate 7 is provided with. a plurality of inwardly extending spurs 8 which spurs 8 bent into engagement with the conical portion 2 upon the interior thereof, whereby the contact plate 7 will be firmly held This contact plate '4' is provided with. the slot 9 formed therein and extending thereinto from its periphery to a point adjacent its center for purposes to be hereinafter set forth.

he usual fusible wire 10 has one end grounded upon the plate 7, as shown at 11, while the opposite end of the fusible wire 10 is carried by the conductor 12 mounted upon the shell 1 of the fuse plug.

From the foregoing description it will be seen that when this ruse plug is in use it should be screwed into a socket in the usual manner. Since the structure 12 will be grounded upon the socket by means of the sleeve 6, while the contact plate 7 will be in its ordinary position, it'is obvious that a circuit will be formed by the fusible wire 10. Of course, if a short circuit is experienced in a set position.

in the circuit in which the fuse plug is carthe lug for a spaced distance, as shown in Fig. 1, whereby it will project to the slot 9 formed in the contact plate 7. Since the lug 15 is also formed of insulated material, it is obvious that notwithstanding the fact that thefusible wirepr ects into the slot 9,

it will not form a one it.

The supporting cars 17 are formed upon the conical portion 2 in parallel relation and the trigger 18 is pivotally mounted upon the ears 17 and it will be understood that this trigger 18 is formed of conducting material. Under normal conditions this trigger 18 is swung upwardly and maintained in an inoperative position, as clearly shown in the drawing.

When this fuse plug is engaged, it will be screwed into the usual socket, and at this time the trigger 18 is out of engagement with the contact plate 7 by being positioned as indicated in Figs-1 and 2. If so desired, it is obvious that the conical portion 2 may be provided with a notch 19 into which the trigger will partially pass whereby a binding action will be had upon the trigger for holding the same in an inoperative. position. If for some reason a short circuit or an overcharge causes the fusible wire 10 to melt, the fuse plug may be removed and at this time the trouble in the .circuit may be corrected. The fuse may then be again inserted al--" though prior to this action the trigger 18 should be swung or pivoted upon the ears 17 so as to pass into the slot 9 as shown clearly in dotted lines in Fig. 1. As this tr'gger 18 is formed of conducting material it' will bear upon the contact plate? within the slot 9 and will also bear upon the projecting end of the second fusible wire 13.. his action of the trigger .18 will form a circuit over the sleeve 6, the second fusible ,wire 13, the

trigger 18, and the contact plate 7. It is of course obvious that if some other over charge is experienced in the circuit in-which the fused plug is used, the second fusible Wire 13 will also m'elt, thus causing the fused plug to positively protect the supporting structure of the fuse plug construction, al-

. though because of the use of the extra fusible wire, the life of the fuse plug willbe greatly prolonged.

It will be obvious that many minor changes may be made in the detail construction of. this invention without departing from the spirit of the device and for this reason it is not intended to limit the construction of this fuse plug to the. specific meas es form herein-shown butto include all silch forms of the invention as properly com'e said shell, a contact sleeve carried by said I shell, a fusible wire connected to said sleeve and said plate, whereby a circuit may be formed, a second fusible wire connected. to

said sleeve and carried by said. shell at a point adjacent said plate, and means for closing the circuit between said second fusible wire and said plate after the first mentioned fusible wire becomes inoperative.

2. In a fuse plug, the combination of an insulated shell, a-eontact sleeve and a contact plate carried by said shell," a ffusible wire connectedwith said plateand'said sleeve, a second fusible wire connectr'adv to said sleeve and also said shell, at a point ad jacent said plate, and a movable trigger carried by said shell, said trigger being adapted to be moved into engagement with said plate and said second fusible wire after the first mentioned fusible wire is melted.

3. In combination with a fuse plu a primary circuit closing means carrieddry said shell and having contact terminals, an auxiliary means carried by said shell and being engageable with said contact terminals at'a time after the first mentioned means becomes inoperative. i

4:. In a fuse plug, the combination of a shell, a fusible wire-carried b said shell, a. contact plate carried by said s ell, said fusible wire being connected to said contact plate, said contact-plate also having a slot formed therein, said shell having a lug formed thereon'in alinement with the-slot in said contact plate, a second carried by said shell, one end of\ said last mentioned fusible wire being supported by fusible wire said lug, and means movably mounted upon said shell and passing into said slot after the first mentions movable wire has become inoperative; whereby the last mentioned means Wlll be heldby said plate in engagement with the second fusible wire.

5. In a fuse plug of the class described, the combination of a shell, a contact sleeve carried-by said shell, 3, contact plate carried by said shell, a fusible wire connected to said the combination of a shell, a sleeve carried by said shell, a contact plate carried by said shell, a fusible wire connected to said sleeve and said contact plate, said contact plate having a slot extending thereinto, said shell having an internal lug formed in alinement with the slot in said plate, a second fusible wire connectedto said sleeve and having one end carried by said lug and projecting into said slot, and a trigger pivotally mounted upon said shell being adapted to be swung into engagement with said contact plate by fitting within said slot and also engage the end of said second fusible wire after the first mentioned fusible wire has become inoperative.

7. In a fuse plug of the class described, the combination of a shell, a contact sleeve carried by said shell, a contact plate carried by said shell, a fusible wire carried by said shell and engaging said sleeve and said contact plate, said plate having a slot extending thereinto, said shell having a lug formed in alinement with said slot, a second fusible wire having one .end connected to said sleeve and the remaining end carried by said lug and extending into said slot, said shell having a notch formed therein, a trigger pivotally mounted upon said shell and normally fitting within said notch, thus being held in an inoperative position, said'trigger being capable of being swung from said notch after the first mentioned fusible wire has become inoperative, thus permitting the trigger to be moved into engagement with said plate within said slot and at the same time engage the projecting end of said second mentioned fusible wire.

In testimony whereof I affix my signature in presence of two witnesses.

JOSEPH A. DUGAN.

Witnesses:

W. A. VINBON, Jon CATHRINER. 

